@misc{indiciae55bfa9596771,
  title = {Visual field changes in early glaucoma and how to recognize them.},
  author = {A Heijl},
  year = {1989},
  doi = {10.1016/0039-6257(89)90062-3},
  url = {https://pubmed.ncbi.nlm.nih.gov/2749505/},
  note = {Source identifier: 2749505}
}